Can closing machine



Oct. 18, 1938. A. N. YORK 2,133,315

CAN CLOSING MACHINE Filed Sept. 1 1, 1936- 4 Sheets-Sheet l 09 ,3; /Z we 72 9 a; //7 me //6 w H 37 2 35 is ,I i T m 77 A 2 ZFIVE 4 BYQ I a 7 ATTORNEYS Oct. 18, 1938. A. N. YORK 2,133,315

' CAN CLOSING MACHINE Filed Sept. 11, 1936 4 Shets-Sheet 3 Oct. 18, 1938. A. N. YORK CAN CLOSING MACHINE Filed Sept. 11, 1936 4 Sheets-Sheet 4 ATTORNEYS I Patented Oct. is, 1938 i 2,133,315

UNITED STATES PATENT OFFICE can CLOSING MACHINE Archibold N. York, Geneva, N. Y., assignor to American Can Company, New York, N. Y., a corporation of New York Application September 11, 1936, Serial No. 100,394

14 Claims. (01. 113-82) The present invention relates to container or the valves are so positioned and locked and can closing machines of the type which have which also prevent operation of the machine valves for moving the cans into and out of a while the valves are so locked. vacuumized can closing chamben'the invention A further object is the provision in such a having particular reference to a hoisting mechn of ele s which Prevent opeletioh 5 anism, embodied in the machine and utilized for of the hoist when there is a vacuum in the can raising the valves out of their seats so that they closing er of the machine and which also may be cleaned and lubricated and for returning prevent Op o of the mac ine W ile t them again to position within their seats. Valves-are out of their seats and until they have Proper care in cleaning and lubricating the been p d and a predetermined vacuum 10 valve seats and valves of vacuum can closing maain created in the c n cl sin mb rchines is essential in maintaining .a tight at be- Num rous other objects and ad a t es o t tween valve and seat to insure against loss of ve o l be app t s it s bette u vacuum in the closing chamber. These valves od rom he following descrip Which,

are usually ponderous and heavy and hard to taken in connection with the accompanying 15 manage although proper care requires that they drawings, discloses a preferred embodiment be removed frequently. Canning factories where thereof. the machines are used to seal filled cans are Referring to the drawings: usually not equipped with machinery for han- Figure 1 is a top plan view of a vacuum can dling these valves and hence considerable dimosing machine embodying the instant inven- 20 culty is sometimes experienced in properly tion, With par s broken a cleaning and lubricating the valves and their Fig.2 is a fragmentary front elevation of the seats. upper part of the machine showing the valves in Th present i v ti contemplates a elfraised position above their seats and showing contained hoist which is built into the machine parts of the hoist for raising an lowering the 25 so that lifting of the valve out-of its seat and s, parts being broken y;

returning it again is made an easy operation 3 is a longitudinal Section Of the pp thereby saving both labor and expense and more part of the closing m the ew b n readily effecting proper working efliciency. iiakeh Substantially along a plane extending An object, therefore, of the invention is the through the vertical axes of the valves; 30 provision of a self-contained hoist in a valve Figs. 4 and 5 are horizontal sectional details type vacuum can closing machine wherein the taken substantially along the lines 4-4, 55 in valve or valves may be lifted from their seats Fig. 3; I for lubricating and cleaning or changing of Figs. 6 and 7 are horizontal sections taken parts and may be returned again to proper posisubstantially along the line 6-6 in Fig. 3, and 35 tion within their seats without dismantling the showing in different positions parts of one of the machine. valves and the mechanism for locking the valve Another object is the provision in such a main a predetermined position before raising, parts chine, of electric controls for governing the rais- I being broken away;

ing and the lowering of the valves relative to Fig. 8 is a sectional detail of the valve locking 4;, their seats so that in lifting the valves the operm an m, h vi w being taken substantially ation of the hoist ceases when they are clear ong the e 8-8 i w parts broken of their seats or in their desired upper position away; where they will be easily accessible and also so Figs. 9 and 10 are sectional details showing 5 that upon returning the valves to their seats, the different positions of parts of the electric conoperation of the hoist ceases when the valves trol devices associated with the valve locking are again in their fully seated position. mechanism, the sections being taken substan- Still another object is the provision in a matially along the line 9-4! in Fig. 3; chine of this character, of a locking mechanism Fig. 11 is a horizontal sectional detail taken for locking the valves in a predetermined posisubstantially along the line ll-Il in Fig. 10; 50

tion in their cycle of rotation or other movement and so that movable parts within the valves are Fig. 12 is a wiring diagram of the electric cir-. properly disposed before the valves are raised, cuits utilized in the machine. the locking mechanism controlling electric de- As a preferred embodiment of the invention the vices which prevent operation of the hoist until drawings disclose the principal parts of a vacuum 55 can closing machine of the character shown in United States Patents 1,969,717, issued August 14, 1934, on "Vacuum machine and 1,985,883, issued January 1, 1935, on "Can feeding machine.' Unsealed cans with their covers loosely held in place as by clinching or otherwise, are introduced into a vacuum chamber where can and cover are united in a sealing connection as by an interfolding of their parts or in any other suitable manner.

The cans are introduced into the vacuum chamber and are discharged therefrom by way of rotating entrance and exit valves which are provided with suitable pockets in which the cans are carried. Cam actuated fingers in the pockets of the entrance valve sweep the pocketed cans carried by this valve into the vacuum chamber at the proper time while similar fingers in the pockets of the exit valve sweep the cans carried by it, out onto a table or other suitable place of discharge.

Each of the valves is removably seated in and is partially surrounded by a housing which prevents the entrance of air into the vacuum chamber as the valves rotate. Closely connected with the valves is the hoisting mechanism for lifting the valves from their seats to permit cleaning I and lubricating and for returning them again into fully seated position. It is to this feature that the invention is particularly directed.

Only suflicient of the can closing machine is herein illustrated anddescribed to provide a clear understanding of the present invention, the hoisting mechanism being shown in some detail.

Such a disclosurepreferably embodies a main supporting frame or housing ll (Fig. 3) having mounted thereon an auxiliary housing l2. These housings enclose a vacuum chamber (indicated by the numeral 13) into which cans l4, havingloosely applied covers 15, areintroduced for vacuumizing and closing or sealing.

The chamber I3 is vacuumized in any suitable or usual manner as by means 'of a suction pump or vacuum tank (not shown) which communicates with a pipe line i! (Fig. 1) leading from the vacuum chamber. The vacuumized cans are closed or sealed in the usual manner by a suitable seaming head [8 (Fig. 3) which is disposed in the vacuum chamber. The seaming head is preferably mounted in a bearing formed in the housing l2.

- The cans [4 are delivered into the vacuum chamber I3 and are discharged therefrom through openings 2| formed in opposite side walls of the frame H and by way of rotatable entrance and exit valves 24, 25 disposed adjacent these openings. The valves operate in and are partially surrounded by valve seats 28, 21 formed in housings 28, 29 bolted to the sides of the main frame.

The valves 24, 25 are rotated in their seats 28, 21 through tongue and groove driving connections 3| with flanged hubs 32 which in turn are keyed to vertical drive shafts 33. The shafts are journaled in bearings 34 formed in brackets 35 which are secured to the sides of the main frame. These shafts are rotated in unison in any suitable manner. a

The valves are provided with a plurality of spaced can carrying pockets 8'! into which the cans l4 are deposited in the usual manner. Each pocket is provided with a. finger 88 mounted on a vertical pin 39 carried in a bearing 4| of the valve, the pin being periodically rocked by a cam 42 mounted on top of each valve. It is these fingers which sweep the cans from the pockets of the entrance valve into the vacuum chamber as the valve rotates. Similar fingers in the exit valve sweep the sealed cans out onto a suitable discharge table 43 (Fig. 1).

, a. pair of elongated elevator screws 56, 51 vertically and centrally disposed over the tops of the valves 24, 25, respectively.

The upper ends of the elevator screws 56, 51 are rotatably carried in bearings 58 formed in the bottom of separate gear cases GI, 62. Gear case BI is formed integrally with a bracket 83 secured by bolts 64 to the top of the housing l2. Similarly gear case 62 is formed on a bracket 65 secured by bolts 68 to the top of the housing I2. The elevator screws 56, 51 are identically supported and connected with their respective valves, therefore it is thought that a description of one of them will suflice for both.

The elevator screw 56, for example, carries a bevel gear 61 which is disposed in its gear case BI, and this bevel gear is connected to its elevator screw by a feather 68 (Fig. 3).

The lower end of the elevator screw is engaged in a threaded nut H which is provided with a pair of oppositely disposed wings 12 projecting from its sides. The wings extend into vertical elongated slots I3 formed in the side wall of a stationary tube 14 which surrounds the elevator screw. The upper end of the tube is keyed against rotation within a collar 15 formed on the bottom of the gear case.

The lower end of the tube 14 extends below the end of the elevator screw and rests on top of a spacer shaft 11. The top of the spacer shaft is provided with a trunnion 18 which is journaled for rotation in a bearing 19 carried in the lower end of the tube. The spacer shaft extends through a central ,bore 8| formed in the valve and has its lower end supported in a recess 82 formed in the top of the valve drive shaft 33.

The spacer shaft 11 is smaller in diameter than the bore 8| with the result that the valve is free to float and thus fit more snugly within its seat. The shaft is feathered in the valve which permits raising and lowering of the latter without getting out of alignment with the tongued driving connection 3| as will be hereinafter more fully explained. It will be evident that the parts just described as being associated with the elevation screw 56 are duplicated in- The upper ends of the sleeves 85 extend above the elevator screw nuts 1| and are formed with in-turned flangesv 88 which surround the elevator screw tubes I4. A pressure distributing collar 92 (Figs. 3 and 4) is disposed inside each sleeve 85 between the flange 88 and the wings 12 of the nut H and is adapted to engage against the sleeve flange when the valve is raised.

By means of this construction and by a rotating'movement in one direction of the elevator The elevator screws 58, 51 are rotated in unison so that both valves are raised or lowered at the same time. This is effected by a cross shaft 95 having its ends mounted in bearings 96 formed in the gear oases 6|, 62. The cross shaft carries bevel gears 91 which mesh with and rotate the elevator screw gears 61 when the cross shaft turns.

The shaft also carries a slip clutch 98 which is disposed in the gear case 6| and which is provided with a worm wheel 99. The worm wheel meshes with a worm IOI secured to a shaft I02 of a reversible electric motor I03 (Fig. 1) mounted on the bracket 63. This motor is the source of power for rotating the cross shaft 95 in either direction.

In raising and lowering the valves 24, 25 the finger timing cams 42 are lifted or lowered with the valves. The cams have no 'rotative movement at any time and are held against rotation in a manner to permit their raising and lowering with the valves. For this purpose the cams are provided with guide blocks I05, I06 (Figs. 2, 3, 6 and 8) which may be bolted to the tops of the cams or otherwise secured in The guide blocks engage vertically disposed guide rods I01. I08 carried in suitable bearings formed in the gear case brackets H, 62, and in the main frame brackets 35. The guide rod I01 is stationary but the rod I09 can be oscillated within its bearings. Rod I08 is rocked on its axis by a handle I09.

To prevent damages to the valve fingers 38 whenthe valves are raised out of their seats the valves are brought to rest in a predetermined position in which position all of the fingers are completely within the valve pockets as shown in Fig. 7. The valves are then looked against rotation by direct holding of the exit valve 25. Since both valves are in effect connected together by the mechanism which rotates them, the locking of the exit valve also serves to lock the entrance valve. This locking is effectedby a slide I II (Figs. 2, '7 and 8) which is carried in a slideway II3 formed in the top of the guide block I06. A cover plate II4 secured to the block holds the slide in its slideway.

At one end the slide III is formed with a locking tongue II6 which is engageable into a notch II1 formed in a collar II8 mounted on and secured to the exit valve sleeve 85. Thus the collar rotates with the valve under normal operation of the machine. When the machine is to be stopped, to prevent locking of the valves it is logged along or moved slowly as by alternate operation of a start and stop switch device, hereinafter referred to, until a notch H1 is in proper position to be engaged by There are a plurality of these notches II1, one for each pocket in the exit valve, and any one of these notches when engaged by the slide tongue III locks the exit valve and through it also the entrance valve against rotation The slide tongue I I8 is moved into engagement with a notch II1 by a cam connection with the any suitable manner.

the locking tongue IIG.

guide rod I08. The end of the slide III opposite the tongue end is formed with a curved section I2I (Figs. 6 and 8) which partially surrounds the guide rodand is provided with a pair of inner cam edges I22, I23.

The'cam edge I22 when the guide rod I08 is' is held against the (Fig. 8) disposed in in unlocked position (Fig. 6) rod by a tension spring I24 a recess I25 of theguide block I06. One end of the spring is hooked into a screw eye I26 secured to the guide block while its opposite end is hooked into a similar screw eye I21 secured to the slide III. This latter screw eye extends through a clearance slot I28 formed in the floor of the slideway II3. A short key I3I fixed in the guide rod I08 engages the cam edge I23 at such a time and holds the slide III in retracted or unlocked position.

When the guide rod I09 is turned, by means of the handle I09, in a counter-clockwise direction, (1. e., from the position shown in Fig. 6 into that shown in Fig. '7) the key I3I is rocked away from the cam edge I23, this action releasing the slide. In this same movement another key I32 much longer than th first key and located in the opposite side of guide rod I08 moves into engagement with the cam edge I22 and then pushes the slide forward against the resistance of the spring I24 thereby moving the tongue II6 into a notch H1 and hence locking the valves against rotation as already described.

The key I32 is of sufficient length to hold the slide III in locked position irrespective of the vertical position of the valve. A clearance groove I33 cut in the block I06 provides for clearance of the key and allows for this vertical movementof the valve and the block. A second clearance groove I34 cut in the block ,I06 provides for freedom of vertical movement relative to the key I3I by allowing the block to clear the key when it is lifted with the valve or returned to lowered position.

Turning of the guide rod I08 to lock the valves against rotation also prepares for the lifting of the valves as well as rendering the machine inoperative until the valves are again unlocked. This is done electrically by means of a double pole hoist motor switch I35 (Figs. 9, 10 and 12) The electric circuits utilized for this work will be hereinafter explained in connection with the wiring diagram illustrated in Fig. 12.

The switch I35 is mounted on the gear case bracket 65 (Figs. 1, 2 and 3) and is formed with a movable element I36 which at times is engaged by the head of a pin I31 carried in a boss I38 formed on thebracket. A cam I39 mounted on the guide rod I 08 raises thepin and the movable switch element when the guide rod I09 has been turned into its valve locking position (as shown in Figs. '1, l0 and 11).

Before the valves can be raised the vacuum in the vacuum chamber I2 must be broken and the chamber brought under atmospheric conditions. This introducing of air into the chamber may be done in any suitable manner either mechanically or manually. To graphically indicate the establishment of such conditions the drawings disclose a two-way valve I43 (Fig. l) I which is located in the vacuum pipe line I1. The position of the valve as shown connects the chamber I3 with the vacuum pipe line. When the handle of the valve is turned counter-clockwise, the pipe line is cut off and the chamber is opened to the atmosphere.

The preventing of the valve lifting action when there is vacuum in the chamber I3 may be accomplished by a vacuum control device (indicated broadly by the numeral I44) which utilizes an electric switch included in the electric circuits used for operation of the lifting motor I63. This will be further mentioned in connection with the description of the wiring diagram (Fig. 12) to follow.

Such a vacuum control device may comprise a sylphon bellows connected with a mercury switch which may be encased in a suitable housing located on the vacuum supply pipe I1 adjacent the closing chamber. A change of degree of vacuum in the pipe and in'the closing chamber acts on the bellows to tilt the mercury switch in accordance with the vacuum condition. This is a wellknown form of control which is often used in vacuum closing machines. A suitable device of this character is disclosed in United States Patent 1,841,326 issued to Lewis W. Eggleston January 12, 1932, on Controlling means.

Provision is also made for limiting the amount of travel of the valves 24, 25 either in their upward movement or in their return. This is done electrically and includes stop switches which may be mounted upon the gear casings 6i, 62. These switches are actuated by movable parts of the valves.

In the valve raising action the top of the exit valve 25 when brought into its upper position engages against the lower end of a pin I41 (Figs. 1, 2, 3 and 5) and lifts the pin which opens an electric circuit. This pin is vertically disposed in suitable bearings formed in the gear case 62. At its upper end the pin carries an arm I48 having at its free end a stud I49 which is guided in a bore formed in a cover of the gear case 62. The guide stud is located directly under a movable element I5I of a normally closed stop switch I52 mounted on top of the gear case.

When the valves are returned to their seats, the wing 12 of the elevator screw nut 1I associated with the entrance valve 24 engages against the wall of the tube 14 at the lower end of the slots 13, bringing the nut to rest. The rotating elevator screw 56 thereupon moves endwise in its threaded seat within the then stationary nut lifting vertically in-its bearing 58 and sliding in the gear 61 at its feather connection 68, as shown in Fig. 3.

The screw 56 then stops turning but stays in its raised position. In this lifting action the upper end of the screw engages against and raises a movable element I55 of a stop switch I56, the element being carried in a bearing I51 formed in the cover of the gear case 6|. The stop switch I56 is mounted on top of the gear case.

Th s lifting of the movable element opens the switch I56 and breaks the hoist motor holding circuit which includes the switch. The open position of the switch therefore constitutes its normal position and the switch stays open or normal during the operation of the machine. The hoist motor holding circuit together with other associated electrical circuits will now be described.

Reference should now be had to the wiring diagram (Fig. 12). The machine motor for operating the main parts of the apparatusis designated in this diagram by the numeral I65 and electric energy for operating this motor is supplied in any suitable manner as by a generator I1I which also supplies current for the hoist motor as well as for the various control circuits. Current passes from the generator by way of a three wire system comprising service wires I12, I13, I14 and through a main service switch Ill and a. solenoid-operated switch I16 when the lat ter is closed. In order to close this switch, control circuits comprising a machine pie-starting and a machine starting circuit are used.

When the valves are being lifted by rotation of the screws 56, 51 current for operating the'hoist motor I03 is taken from the service wires I12, I13, I14 and is transmitted to that motor by way of service wires I11, I16, I16 and thence through one or the other of motor reversing solenoid-operated switches I6I, I62 one of which is closed at the time. The selective closing of switch I8I or switch I82 is eflected by the use of control circuits comprising a valve elevating starting circuit or a valve lowering starting cIrerator by way of a step-down transformer I66.

The primary side or this transformer is conrlifcted to the service wires I11, I19- by wires I66,

The machine pre-starting circuit is only closedwhen the valves 24, 25 are in proper seated and operating position and unlocked and only when there is a predetermined degree of vacuum w thin the chamber I3. When in such condition the movable element I36 of the switch I36 is in the position shown in dotted lines, engaging with lower switch contacts I86, I89. Furthermore, when the valve and the vacuum in chamber I3 are in the condition above described a mercury switch I90 of the vacuum control device I44 is in the tilted position indicated in dotted lines, this closing the gap between switch contacts I9I, I92.

Electric energy activating the machine prestartfng circuit passes from the secondary side of the transformer I65 through a wire I95, movable element I36 of switch I35, a wire I96, mercury switch I90 at contacts I9I, I92, a wire I91, a solenoid I98 and back to the transformer by way of a wire I99. This flow of current energizes the solenoid I 98 and thus closes a normally open relay 20I.

Relay MI is included in the machine starting circuit together with machine start and stop switches 202, 203 which control the normal starting and stopping of the machine motor I 65. To set the machine in operation the machine starting circuit is closed by momentarily closing the starting switch 202. Electric energy from the generator I1I then passes from service wire I14 through a wire 205, starting switch 202, a wire 206, stop switch 203, a wire 201, closed relay 20I, a wire 208, a solenoid 209, a wire 2, back into service wire I12. This flow of current from the transformer energizes the solenoid 209 which in turn closes the machine motor switch I 16 thereby transmitting energy from the generator I1I directly to the machine motor I65.

Closing of the machine motor switch I16 automatically establishes a machine holding circuit which maintains continued operation of the motor I65 after release of the starting switch 202.

The holding circuit is established by the closing the motor switch I16 closed.

Provision is made for stopping operation 0! the machine in case the vacuum condition in the closing chamber I3 should fall below a predetermined degree. For this purpose the machine holding circuit, keeping the machine motor I65 in operation, is maintained under the control of the machine pre-starting circuit. Thus a falling oil of the vacuum, as detected by the vacuum control devices I44, immediately tilts the mercury switch I in the opposite position (shown in full lines, Fig. 12) so that the gap between the contacts I9I, I92 is opened. This breaks the machine pre-starting circuit with the result that the solenoids I98, 209 are de-energized and the, machine holding circuit is thus broken causing the machine motor switch I16 to open. This stops the operation of the motor I65 and hence stops operation of the machine. The machine motor cannot then be started again until the degree of vacuum in the closing chamber is high enough to again tilt the mercury switch I90 to close the gap between its contacts I9I, I92.

Normal stopping of the machine is effected by opening the machine stop switch 203. This will deenergize the solenoid 209 and open the machine motor switch I16 even if suillcient vacuum is. maintained in the closing chamber.

The valve elevating starting circuit and the valve lowering starting circuit which are associated with the operation of the hoist motor I03 for rotating the elevator screws 56, 51 in raising and lowering the valves 24, 25 also include the hoist motor switch I35 and the mercury switch I90, these switches being closed in such a manner as to entirely out out the circuits associated with the machine motor I65. It will be remembered that before raising the valves the vacuum in the can closing chamber I3 must be dissipated, the machine stopped, and the valves locked in a pre- .determined position as hereinbefore explained.

Locking of the valves disengages the movable element I36 of the switch I35 from the contacts I88, I89 and brings it into engagement with a pair of new contacts 2I4, 2I5 shown in full lines in Fig. 12. This breaks the machine motor circuits and prevents operation of the machine motor I65 until the valves are again unlocked which ordinarily does not .take place until after the valves have been raised out'of their seats and again returned.

Dissipation of the vacuum in the can closing chamber I3 rocks the mercury switch I90 to a position where the contacts I9I, I92 are opened as has already been described. The switch I90 also has a. pair of contacts 2I6, 2" which are closed when contacts I9I, I92 are opened and are opened when contacts I9I, I92 are closed. It is the closing of contacts 216, 2I1 which permits use of the valve elevating circuit and the holding circuit associated therewith. This will now be explained.

To raise the valves 24, 25 out of their seats, the valve elevating starting circuit is completed by pressing a starting switch 2I8 to bring it into its starting position, indicated by dotted lines in Fig. 12. Electric energy from the secondary side of the transformer I85 then passes along wire I95, a wire 2I9, switch I35, a wire 220, an emergency switch 22I, a wire 222, contacts 2I6, 2I1 of switch I90, a wire 223, stop switch I52, a wire 224, a valve lowering start switch 225, a wire 225, closed starting switch 2I9, a wire 221, a solenoid 228, wires 229, Ml, I99 back to the transformer.

Electric energy passing through this circuit.

energizes the solenoid 229 which closes the hoist motor switclif I8I. Closing of this switch permits electric energy from the generator "I to .pass from the service wires I11, I18, I19 through the switch I8I, wires 236, 231, 238 and thence into the motor I03 causing it to turn the elevator screws 56, 51 in the proper direction for raising the valves 24,25 out of their seats as hereinbefore explained.

Since closing of the starting switch 2 I9 is only a momentary action, a valve elevating holding circuit is established simultaneously with "the closing of the motor switch IN and this keeps the motor I03 in continuous operation until the elevating of the valves is completed, this being when the valves are clear of their seats.

Thevalve elevating holding circuit is established by closing of a single contact 242 formed as a part of switch I8I and which automatically closes with the switch. Thus when the starting switch 2I8 resumes its normal open position as shownin full lines in Fig. 12, energy from "the transformer passes from the wire 226 along a wire 243, through contact 242, a wire 244, wire 221, solenoid 228, and wires 229, 23I, I99 back to the transformer. This circuit maintains the solenoid 229 energized while the starting switch is open and thus keeps the motor switch I8I closed.

When the valves 24, 25 reach the top of their desired travel they open the stop-switch I52 as hereinbefore explained. This breaks the valve elevating holding circuit just described. The solenoid 228 is thus deenergized and the switch I8I is opened in the usual way. This stops the motor I03 and further rotation of the elevator screws 56, 51 which thus stops further raising of the valves.

Lowering of the valves 24, 25 again to position within their seats is effected by similar circuits which are established to cause motor I03 to rotate the elevator screws 56, 51 in a reverse direction. A valve lowering starting circuit is established by pressing the starting switch 225 and moving it into the position shown in dotted lines in Fig. 12. Electric energy from the transformer I95 is then transmitted by way of wires I95, 2I9, switch I35, wire 220, emergency switch 22I, wire 222, a connecting wire 245, closed stop switch I55 (dotted position), a wire 241, starting switch 2I8, a wire 249, closed starting switch 225, wires 249, 25I, a solenoid 252, wires 253, 23I, I99 back to the transformer.

Energy passing along this valve lowering startingcircuit energizes the solenoid 252 which closes the hoist motor switch I82., Closing of this switch permits energy to pass from the service wires I11, I18, I19, through theswitch I82, and wires 256, 251, 258, into the hoist motor I03. This flow of current through the motor being in the opposite direction to that described for the valve elevating action causes the motor and the screws 55, 51, to

rotate in reverse and hence to lower the valves into their seats.

A valve lowering holding circuit is established to maintain continued operation of the hoist motor after the starting switch 225 is released and returned to its normally open position. This holding circuit is established by a single contact 26I which is associated with the main switch I92 and which closes when the main switch closes. Electric energy then passes from the wire 248, along a wire 262', contact 26I, wires 253, I,

solenoid 252, wires 250, 23L I00 back in the transformer. This keeps the solenoid 252 energized and hence maintains the main switch I02 in closed position during" lowering of the valves.

When the valves 24, 25 are again returned within their seats, the closed stop switch I55 is again opened to its normal position as herelnbefore explained to break the valve lowering holding circuit. The solenoid 252 becoming de-energized, causes the main switch I02 to open and to stop the hoist motor I00. The valves 24, 25 may now be unlocked after which if the machine is to be operated the foregoing steps will be carried out.

A brief recapitulation of the operation of the elevator screws 55, 51 through one complete cycle including raising and lowering of the valves 24, 25, will now be given. Before actually beginning the cycle and as a preliminary step, the machine motor I65 must necessarily be stopped. Then the exit valve 25 is manually locked by movement of the locking handle I00 and this also looks valve 24. The movable element I36 of the switch I35- is thereby brought into engagement with the upper contacts 2, 2I5 which are thus included as a Part of a circuit which connects with the hoist motor I03. Electric switch I52 at this time is closed and switch I56 is open.

The starting switch 2I8 is pressed in and the cycle begins as current established by the switch energizes the hoisting motor I03 and the elevator screws 56, 51 start rotation. There is a slight time lag before the entrance valve 24 is lifted as its turning screw 56 moves down within the nut 'II permitting the descending screw head to release the movable element I55 of switch I56 which action closes the switch. Both valves 24, 25 move out of their seats and travel up along the lengths of their rotating screws 56, 51.

When the raised valves reach their upper limit of travel the exit valve 25 opens switch I52 by engagement with the movable switch element I5I. This breaks the current and stops the motor I03 and the screws 56, 51 cease rotation.

To return the valves to their seats starting switch 225 is pressed in and the motor I03 thereupon operates in a reverse direction. It should be recalled that switch I56 is now closed and switch I52 is open. The motor rotating the screws 56, 51 in a reverse direction lowers the valves into their seats. The movable element I5I upon being disengaged closes the switch I52.

The effect of the final phase of rotation of the elevator screw 56 after the entrance valve 24 is fully seated is to slightly elevate or back up the screw and to liftits head against and to raise the movable element I55 of the switch I 56 thereby opening the switch. This breaks the hoist motor reverse circuit and the motor I03 stops, the screws 56, 51 cease turning. The cycle is completed.

The valves thus fully reseated may then be unlocked or freed for rotation and for normal machine operation by manipulation of the locking handle I 09.

It will be recalled that an emergency switch 22I, has been included in the valve elevating and valve lowering, starting and holding circuits. This is used to manually terminate the action of any of these circuits at any time before comple tion of their respective cycles. It is therefore a safety feature and by manually opening a circuit at this switch the valves can be brought to rest in any desired position whether they are being raised or lowered.

It is thought that the invention and many of ent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope or the invention or sacrificing all of its material advantages, the form hereinbefore described "being merely a preferred embodiment thereof.

I claim:

1. In a vacuum machine for cans, the combination of a housing enclosing a vacuum chamber and having openings for the passage of cans therethrough, valve seats connected with said housing adjacent said openings, valves floatingly disposed in and upwardly from said seats for normally conveying cans into and out of said vacuum chamber, rotatable elevator screws anchored in said housing as a'permanent part thereof and rotatably connected with said valves for moving the latter vertically relative to their seats for lubrication and cleaning, and driving elements for rotating said elevator screws in one direction to lift said valves out of their seats and fully seated position.

2. In a vacuum machine for cans, the combination of a housing enclosing a vacuum chamber and having openings for the passage of cans therethrough, valve seats secured to said housing adjacent said openings, rotatable valves disposed ln and upwardly movable from said seats for conveying cans to and from said vacuum chamber, rotatable elevator screws anchored in said housing as a permanent part thereof and rotatable in two directions having connection with said valves for moving the latter vertically to clear their seats or to reseat the valves after clearance, a driving element connecting with said elevator screws for rotating them in unison, and a reversible electric motor for rotating said driving element in either direction to raise and lower said valves in unison.

3. In a vacuum machine for cans, the combination of a housing enclosing a vacuum chamber and having openings for the passage of cans therethrough, valve seats in said housing adjacent said openings, rotatable valves disposed and upwardly movable in said seats for conveying cans to and from said vacuum chamber, means for rotating said valves, means self-contained in said housing and including an electric motor for lifting the valves from their seats, and electric devices operable by engagement with one of said valves while being lifted by said lifting means for stopping operation of said electric motor when said valves are in a predetermined lifted position.

4. In a vacuum machine for cans, the combination of a housing enclosing a vacuum chamber and having openings for the passage of cans therethrough, valve seats connected with said housing adjacent said openings, valves disposed and upwardly movable in said seats for conveying cans into and out of said chamber, means located -in said housing and including an electric motor electric motor and hence stopping further seating movement of said valves when the latter are returned to fully seated position.

5. In a vacuum machine for cans, the combination of a housing enclosing a vacuum chamber and having openings for the passage of cans therethrough, valve seats connected with said housing adjacent said openings, valves disposed and upwardly movable in said seats for conveying cans into and out oi said chamber, fingers in said valves for ejecting cans therefrom, cams adjacent said valves for actuating said fingers, means self-contained in said housing for removing the valves from their seats or for again returning them to fully seated position and for moving the cams with the valves, and devices engaging said cams for maintaining said fingers in predetermined relation with said valves while the latter are moved relative to their seats.

6. In a vacuum can closing machine, the combination of a housing enclosing a vacuum chamber and having openings for the passage of cans therethrough, can closing mechanism located in said vacuum chamber for closing said cans in vacuum, valve seats in said housing adjacent said openings, rotatable valves disposed and upwardly movable in said seats for conveying cans to and from said closing mechanism, a device for dissipating the vacuum in said closing chamber, instrumentalities for locking said valves against rotation and in a predetermined position of their cycle, means self-contained in said housing for removing thevalves from their seats or for again returning them to fully seated position while so locked and while said vacuum is dissipated from said chamber, and electric devices operable by said locking'instrumentalities for rendering the said can closing mechanism inoperable while the valves are locked.

'Z. In a vacuum machine for cans, the combination of a housing having a valve seat, a valve rotatably disposed and upwardly movable in said seat and adapted to confine a vacuum chamber, said valve presenting cans for vacuumization in said chamber, means self-contained in said housing and including a rotatable elevator screw mounted on the vertical axis of said valve and anchored in said housing as a permanent part thereof and rotatably loosely connected with the valve for lifting it to a position clear of its seat, and means for rotating said elevator screw when said vacuum chamber is not under vacuum.

8. In a vacuum machine for cans, the combination of a housing enclosing a vacuum chamber and having openings for the passage of cans therethrough, valve seats connected with said housing adjacent said openings, valves disposed and upwardly movable in said seats for conveying cans to and from said' closing chamber, a device for dissipating the vacuum in said closing chamber, means self-contained in the said housing for removing the valves from their seats or for again returning them to fully seated position while the vacuum of said chamber is dissipated, means for actuating said valve removing or said valve returning means, and manually operated electric devices for stopping said actuating means to arrest movement of said valves .at any desired position in their path of travel during their removal from or return to their seats.

9. In a vacuum machine for cans, the combination of a housing having valve seats, a valve movably disposed in each seat and adapted to confine a vacuum chamber, one of said valves presenting 0 cans for vacuumization in said chamber, machine electric devices including an electric motor and starting and holding circuits for moving said valves in their seats while said chamber is vacuumized, elevator hoist means connected with said valve, hoist electric devices including an electric motor and starting and holding circuits for operating said elevator hoist means to remove said valves from their seats for lubricating and cleaning when said chamber is not vacuumized and to also return said valves to their seats, and electric devices common to the starting and holding circuits of both electric motors for selectively rendering one of the latter inoperative.

10. In a vacuum machine for cans, the combination of a housing having a valve seat, a valve rotatably disposed in said seat and adapted to confine a vacuum chamber, said valve presenting cans for vacuumization in said chamber, and selfcontained means within said housing and axially disposed relative to said valve for lifting the latter to a position clear of its seat.

ll. In a vacuum machine for cans, the combination of a housing having a valve surrounding seat, a valve disposed for vertical movement within and relative to said seat and adapted to confine a vacuum chamber, said valve being adapted to introduce cans into said chamber for vacuumizing therein, and means located in said housing and operatively connected. to said valve for moving the valve vertically relative to its seat to permit lubricating and cleaning.

' 12. In a vacuum machine for cans, the combination of a housing enclosing a vacuum chamber and having an opening for the passage of cans therethrough, a valve surrounding seat connected with said housing adjacent said opening, a valve movably disposed within said seat for moving cans relative to said housing and said vacuum chamber, and means located in said housing ancioperatively connected to said valve for elevating the valve from its seat and for thereafter lowering it into fully seated position.

13. In a vacuum machine for cans, the combination of a housing enclosing a vacuum chamber and having openings for the passage of cans therethrough, valve seats secured to said housing adjacentsaid openings, rotatable valves disposed in and upwardly movable from said seats for conveying cans to and from said vacuum chamber, means Ior dissipating the vacuum in said chamber, means self-contained in said housing and including an electric motor for removing the valves from their seats, and means operable only after said vacuum has been dissipated from said chamber for eflecting said valve removing operation.

14. In a vacuum machine for cans, the combination of a housing enclosing a vacuum chamber and having openings for the passage of cans therethrough, valve seats connected with said housing adjacent said openings, rotatable valves disposed in and vertically movable relative to said seats for conveying cans into and out 0! said chamber, instrumentalities for locking said valves against rotation and in a predetermined position of their cycle, and means self-contained in said housing for moving the valves vertically from their seats or for again returning them to fully seated position while so locked.

ARCHIBOLD N. YORK. 

